*** a/src/backend/nodes/makefuncs.c
--- b/src/backend/nodes/makefuncs.c
***************
*** 508,510 **** makeDefElemExtended(char *nameSpace, char *name, Node *arg,
--- 508,535 ----
  
  	return res;
  }
+ 
+ /*
+  * makeFuncCall -
+  *
+  * Initialize a FuncCall struct with the information every caller must
+  * supply.  Any non-default parameters have to be handled by the
+  * caller.
+  *
+  */
+ 
+ FuncCall *
+ makeFuncCall(List *name, List *args, int location)
+ {
+ 	FuncCall *n = makeNode(FuncCall);
+ 	n->funcname = name;
+ 	n->args = args;
+ 	n->location = location;
+ 	n->agg_order = NIL;
+ 	n->agg_star = FALSE;
+ 	n->agg_distinct = FALSE;
+ 	n->func_variadic = FALSE;
+ 	n->over = NULL;
+ 	return n;
+ }
+ 
*** a/src/backend/parser/gram.y
--- b/src/backend/parser/gram.y
***************
*** 10487,10502 **** a_expr:		c_expr									{ $$ = $1; }
  				}
  			| a_expr AT TIME ZONE a_expr			%prec AT
  				{
! 					FuncCall *n = makeNode(FuncCall);
! 					n->funcname = SystemFuncName("timezone");
! 					n->args = list_make2($5, $1);
! 					n->agg_order = NIL;
! 					n->agg_star = FALSE;
! 					n->agg_distinct = FALSE;
! 					n->func_variadic = FALSE;
! 					n->over = NULL;
! 					n->location = @2;
! 					$$ = (Node *) n;
  				}
  		/*
  		 * These operators must be called out explicitly in order to make use
--- 10487,10495 ----
  				}
  			| a_expr AT TIME ZONE a_expr			%prec AT
  				{
! 					$$ = (Node *) makeFuncCall(SystemFuncName("timezone"),
! 											   list_make2($5, $1),
! 											   @2);
  				}
  		/*
  		 * These operators must be called out explicitly in order to make use
***************
*** 10548,10660 **** a_expr:		c_expr									{ $$ = $1; }
  				{ $$ = (Node *) makeSimpleA_Expr(AEXPR_OP, "~~", $1, $3, @2); }
  			| a_expr LIKE a_expr ESCAPE a_expr
  				{
! 					FuncCall *n = makeNode(FuncCall);
! 					n->funcname = SystemFuncName("like_escape");
! 					n->args = list_make2($3, $5);
! 					n->agg_order = NIL;
! 					n->agg_star = FALSE;
! 					n->agg_distinct = FALSE;
! 					n->func_variadic = FALSE;
! 					n->over = NULL;
! 					n->location = @2;
! 					$$ = (Node *) makeSimpleA_Expr(AEXPR_OP, "~~", $1, (Node *) n, @2);
  				}
  			| a_expr NOT LIKE a_expr
  				{ $$ = (Node *) makeSimpleA_Expr(AEXPR_OP, "!~~", $1, $4, @2); }
  			| a_expr NOT LIKE a_expr ESCAPE a_expr
  				{
! 					FuncCall *n = makeNode(FuncCall);
! 					n->funcname = SystemFuncName("like_escape");
! 					n->args = list_make2($4, $6);
! 					n->agg_order = NIL;
! 					n->agg_star = FALSE;
! 					n->agg_distinct = FALSE;
! 					n->func_variadic = FALSE;
! 					n->over = NULL;
! 					n->location = @2;
  					$$ = (Node *) makeSimpleA_Expr(AEXPR_OP, "!~~", $1, (Node *) n, @2);
  				}
  			| a_expr ILIKE a_expr
  				{ $$ = (Node *) makeSimpleA_Expr(AEXPR_OP, "~~*", $1, $3, @2); }
  			| a_expr ILIKE a_expr ESCAPE a_expr
  				{
! 					FuncCall *n = makeNode(FuncCall);
! 					n->funcname = SystemFuncName("like_escape");
! 					n->args = list_make2($3, $5);
! 					n->agg_order = NIL;
! 					n->agg_star = FALSE;
! 					n->agg_distinct = FALSE;
! 					n->func_variadic = FALSE;
! 					n->over = NULL;
! 					n->location = @2;
  					$$ = (Node *) makeSimpleA_Expr(AEXPR_OP, "~~*", $1, (Node *) n, @2);
  				}
  			| a_expr NOT ILIKE a_expr
  				{ $$ = (Node *) makeSimpleA_Expr(AEXPR_OP, "!~~*", $1, $4, @2); }
  			| a_expr NOT ILIKE a_expr ESCAPE a_expr
  				{
! 					FuncCall *n = makeNode(FuncCall);
! 					n->funcname = SystemFuncName("like_escape");
! 					n->args = list_make2($4, $6);
! 					n->agg_order = NIL;
! 					n->agg_star = FALSE;
! 					n->agg_distinct = FALSE;
! 					n->func_variadic = FALSE;
! 					n->over = NULL;
! 					n->location = @2;
  					$$ = (Node *) makeSimpleA_Expr(AEXPR_OP, "!~~*", $1, (Node *) n, @2);
  				}
  
  			| a_expr SIMILAR TO a_expr				%prec SIMILAR
  				{
! 					FuncCall *n = makeNode(FuncCall);
! 					n->funcname = SystemFuncName("similar_escape");
! 					n->args = list_make2($4, makeNullAConst(-1));
! 					n->agg_order = NIL;
! 					n->agg_star = FALSE;
! 					n->agg_distinct = FALSE;
! 					n->func_variadic = FALSE;
! 					n->over = NULL;
! 					n->location = @2;
  					$$ = (Node *) makeSimpleA_Expr(AEXPR_OP, "~", $1, (Node *) n, @2);
  				}
  			| a_expr SIMILAR TO a_expr ESCAPE a_expr
  				{
! 					FuncCall *n = makeNode(FuncCall);
! 					n->funcname = SystemFuncName("similar_escape");
! 					n->args = list_make2($4, $6);
! 					n->agg_order = NIL;
! 					n->agg_star = FALSE;
! 					n->agg_distinct = FALSE;
! 					n->func_variadic = FALSE;
! 					n->over = NULL;
! 					n->location = @2;
  					$$ = (Node *) makeSimpleA_Expr(AEXPR_OP, "~", $1, (Node *) n, @2);
  				}
  			| a_expr NOT SIMILAR TO a_expr			%prec SIMILAR
  				{
! 					FuncCall *n = makeNode(FuncCall);
! 					n->funcname = SystemFuncName("similar_escape");
! 					n->args = list_make2($5, makeNullAConst(-1));
! 					n->agg_order = NIL;
! 					n->agg_star = FALSE;
! 					n->agg_distinct = FALSE;
! 					n->func_variadic = FALSE;
! 					n->over = NULL;
! 					n->location = @2;
  					$$ = (Node *) makeSimpleA_Expr(AEXPR_OP, "!~", $1, (Node *) n, @2);
  				}
  			| a_expr NOT SIMILAR TO a_expr ESCAPE a_expr
  				{
! 					FuncCall *n = makeNode(FuncCall);
! 					n->funcname = SystemFuncName("similar_escape");
! 					n->args = list_make2($5, $7);
! 					n->agg_order = NIL;
! 					n->agg_star = FALSE;
! 					n->agg_distinct = FALSE;
! 					n->func_variadic = FALSE;
! 					n->over = NULL;
! 					n->location = @2;
  					$$ = (Node *) makeSimpleA_Expr(AEXPR_OP, "!~", $1, (Node *) n, @2);
  				}
  
--- 10541,10606 ----
  				{ $$ = (Node *) makeSimpleA_Expr(AEXPR_OP, "~~", $1, $3, @2); }
  			| a_expr LIKE a_expr ESCAPE a_expr
  				{
! 					FuncCall *n = makeFuncCall(SystemFuncName("like_escape"),
! 											   list_make2($3, $5),
! 											   @2);
!                     $$ = (Node *) makeSimpleA_Expr(AEXPR_OP, "~~", $1, (Node *) n, @2);
! 
  				}
  			| a_expr NOT LIKE a_expr
  				{ $$ = (Node *) makeSimpleA_Expr(AEXPR_OP, "!~~", $1, $4, @2); }
  			| a_expr NOT LIKE a_expr ESCAPE a_expr
  				{
! 					FuncCall *n = makeFuncCall(SystemFuncName("like_escape"),
! 											   list_make2($4, $6),
! 											   @2);
  					$$ = (Node *) makeSimpleA_Expr(AEXPR_OP, "!~~", $1, (Node *) n, @2);
  				}
  			| a_expr ILIKE a_expr
  				{ $$ = (Node *) makeSimpleA_Expr(AEXPR_OP, "~~*", $1, $3, @2); }
  			| a_expr ILIKE a_expr ESCAPE a_expr
  				{
! 					FuncCall *n = makeFuncCall(SystemFuncName("like_escape"),
! 											   list_make2($3, $5),
! 											   @2);
  					$$ = (Node *) makeSimpleA_Expr(AEXPR_OP, "~~*", $1, (Node *) n, @2);
  				}
  			| a_expr NOT ILIKE a_expr
  				{ $$ = (Node *) makeSimpleA_Expr(AEXPR_OP, "!~~*", $1, $4, @2); }
  			| a_expr NOT ILIKE a_expr ESCAPE a_expr
  				{
! 					FuncCall *n = makeFuncCall(SystemFuncName("like_escape"),
! 											   list_make2($4, $6),
! 											   @2);
  					$$ = (Node *) makeSimpleA_Expr(AEXPR_OP, "!~~*", $1, (Node *) n, @2);
  				}
  
  			| a_expr SIMILAR TO a_expr				%prec SIMILAR
  				{
! 					FuncCall *n = makeFuncCall(SystemFuncName("similar_escape"),
! 											   list_make2($4, makeNullAConst(-1)),
! 											   @2);
  					$$ = (Node *) makeSimpleA_Expr(AEXPR_OP, "~", $1, (Node *) n, @2);
  				}
  			| a_expr SIMILAR TO a_expr ESCAPE a_expr
  				{
! 					FuncCall *n = makeFuncCall(SystemFuncName("similar_escape"),
! 											   list_make2($4, $6),
! 											   @2);
  					$$ = (Node *) makeSimpleA_Expr(AEXPR_OP, "~", $1, (Node *) n, @2);
  				}
  			| a_expr NOT SIMILAR TO a_expr			%prec SIMILAR
  				{
! 					FuncCall *n = makeFuncCall(SystemFuncName("similar_escape"),
! 											   list_make2($5, makeNullAConst(-1)),
! 											   @2);
  					$$ = (Node *) makeSimpleA_Expr(AEXPR_OP, "!~", $1, (Node *) n, @2);
  				}
  			| a_expr NOT SIMILAR TO a_expr ESCAPE a_expr
  				{
! 					FuncCall *n = makeFuncCall(SystemFuncName("similar_escape"),
! 											   list_make2($5, $7),
! 											   @2);
  					$$ = (Node *) makeSimpleA_Expr(AEXPR_OP, "!~", $1, (Node *) n, @2);
  				}
  
***************
*** 11089,11185 **** c_expr:		columnref								{ $$ = $1; }
   */
  func_expr:	func_name '(' ')' over_clause
  				{
! 					FuncCall *n = makeNode(FuncCall);
! 					n->funcname = $1;
! 					n->args = NIL;
! 					n->agg_order = NIL;
! 					n->agg_star = FALSE;
! 					n->agg_distinct = FALSE;
! 					n->func_variadic = FALSE;
  					n->over = $4;
- 					n->location = @1;
  					$$ = (Node *)n;
  				}
  			| func_name '(' func_arg_list ')' over_clause
  				{
! 					FuncCall *n = makeNode(FuncCall);
! 					n->funcname = $1;
! 					n->args = $3;
! 					n->agg_order = NIL;
! 					n->agg_star = FALSE;
! 					n->agg_distinct = FALSE;
! 					n->func_variadic = FALSE;
  					n->over = $5;
- 					n->location = @1;
  					$$ = (Node *)n;
  				}
  			| func_name '(' VARIADIC func_arg_expr ')' over_clause
  				{
! 					FuncCall *n = makeNode(FuncCall);
! 					n->funcname = $1;
! 					n->args = list_make1($4);
! 					n->agg_order = NIL;
! 					n->agg_star = FALSE;
! 					n->agg_distinct = FALSE;
  					n->func_variadic = TRUE;
  					n->over = $6;
- 					n->location = @1;
  					$$ = (Node *)n;
  				}
  			| func_name '(' func_arg_list ',' VARIADIC func_arg_expr ')' over_clause
  				{
! 					FuncCall *n = makeNode(FuncCall);
! 					n->funcname = $1;
! 					n->args = lappend($3, $6);
! 					n->agg_order = NIL;
! 					n->agg_star = FALSE;
! 					n->agg_distinct = FALSE;
  					n->func_variadic = TRUE;
  					n->over = $8;
- 					n->location = @1;
  					$$ = (Node *)n;
  				}
  			| func_name '(' func_arg_list sort_clause ')' over_clause
  				{
! 					FuncCall *n = makeNode(FuncCall);
! 					n->funcname = $1;
! 					n->args = $3;
  					n->agg_order = $4;
- 					n->agg_star = FALSE;
- 					n->agg_distinct = FALSE;
- 					n->func_variadic = FALSE;
  					n->over = $6;
- 					n->location = @1;
  					$$ = (Node *)n;
  				}
  			| func_name '(' ALL func_arg_list opt_sort_clause ')' over_clause
  				{
! 					FuncCall *n = makeNode(FuncCall);
! 					n->funcname = $1;
! 					n->args = $4;
  					n->agg_order = $5;
- 					n->agg_star = FALSE;
- 					n->agg_distinct = FALSE;
  					/* Ideally we'd mark the FuncCall node to indicate
  					 * "must be an aggregate", but there's no provision
  					 * for that in FuncCall at the moment.
  					 */
- 					n->func_variadic = FALSE;
  					n->over = $7;
- 					n->location = @1;
  					$$ = (Node *)n;
  				}
  			| func_name '(' DISTINCT func_arg_list opt_sort_clause ')' over_clause
  				{
! 					FuncCall *n = makeNode(FuncCall);
! 					n->funcname = $1;
! 					n->args = $4;
  					n->agg_order = $5;
- 					n->agg_star = FALSE;
  					n->agg_distinct = TRUE;
- 					n->func_variadic = FALSE;
  					n->over = $7;
- 					n->location = @1;
  					$$ = (Node *)n;
  				}
  			| func_name '(' '*' ')' over_clause
--- 11035,11088 ----
   */
  func_expr:	func_name '(' ')' over_clause
  				{
! 					FuncCall *n = makeFuncCall($1, NIL, @1);
  					n->over = $4;
  					$$ = (Node *)n;
  				}
  			| func_name '(' func_arg_list ')' over_clause
  				{
! 					FuncCall *n = makeFuncCall($1, $3, @1);
  					n->over = $5;
  					$$ = (Node *)n;
  				}
  			| func_name '(' VARIADIC func_arg_expr ')' over_clause
  				{
! 					FuncCall *n = makeFuncCall($1, list_make1($4), @1);
  					n->func_variadic = TRUE;
  					n->over = $6;
  					$$ = (Node *)n;
  				}
  			| func_name '(' func_arg_list ',' VARIADIC func_arg_expr ')' over_clause
  				{
! 					FuncCall *n = makeFuncCall($1, lappend($3, $6), @1);
  					n->func_variadic = TRUE;
  					n->over = $8;
  					$$ = (Node *)n;
  				}
  			| func_name '(' func_arg_list sort_clause ')' over_clause
  				{
! 					FuncCall *n = makeFuncCall($1, $3, @1);
  					n->agg_order = $4;
  					n->over = $6;
  					$$ = (Node *)n;
  				}
  			| func_name '(' ALL func_arg_list opt_sort_clause ')' over_clause
  				{
! 					FuncCall *n = makeFuncCall($1, $4, @1);
  					n->agg_order = $5;
  					/* Ideally we'd mark the FuncCall node to indicate
  					 * "must be an aggregate", but there's no provision
  					 * for that in FuncCall at the moment.
  					 */
  					n->over = $7;
  					$$ = (Node *)n;
  				}
  			| func_name '(' DISTINCT func_arg_list opt_sort_clause ')' over_clause
  				{
! 					FuncCall *n = makeFuncCall($1, $4, @1);
  					n->agg_order = $5;
  					n->agg_distinct = TRUE;
  					n->over = $7;
  					$$ = (Node *)n;
  				}
  			| func_name '(' '*' ')' over_clause
***************
*** 11194,11222 **** func_expr:	func_name '(' ')' over_clause
  					 * so that later processing can detect what the argument
  					 * really was.
  					 */
! 					FuncCall *n = makeNode(FuncCall);
! 					n->funcname = $1;
! 					n->args = NIL;
! 					n->agg_order = NIL;
  					n->agg_star = TRUE;
- 					n->agg_distinct = FALSE;
- 					n->func_variadic = FALSE;
  					n->over = $5;
- 					n->location = @1;
  					$$ = (Node *)n;
  				}
  			| COLLATION FOR '(' a_expr ')'
  				{
! 					FuncCall *n = makeNode(FuncCall);
! 					n->funcname = SystemFuncName("pg_collation_for");
! 					n->args = list_make1($4);
! 					n->agg_order = NIL;
! 					n->agg_star = FALSE;
! 					n->agg_distinct = FALSE;
! 					n->func_variadic = FALSE;
! 					n->over = NULL;
! 					n->location = @1;
! 					$$ = (Node *)n;
  				}
  			| CURRENT_DATE
  				{
--- 11097,11112 ----
  					 * so that later processing can detect what the argument
  					 * really was.
  					 */
! 					FuncCall *n = makeFuncCall($1, NIL, @1);
  					n->agg_star = TRUE;
  					n->over = $5;
  					$$ = (Node *)n;
  				}
  			| COLLATION FOR '(' a_expr ')'
  				{
! 					$$ = (Node *) makeFuncCall(SystemFuncName("pg_collation_for"),
! 											   list_make1($4),
! 											   @1);
  				}
  			| CURRENT_DATE
  				{
***************
*** 11268,11283 **** func_expr:	func_name '(' ')' over_clause
  					 * Translate as "now()", since we have a function that
  					 * does exactly what is needed.
  					 */
! 					FuncCall *n = makeNode(FuncCall);
! 					n->funcname = SystemFuncName("now");
! 					n->args = NIL;
! 					n->agg_order = NIL;
! 					n->agg_star = FALSE;
! 					n->agg_distinct = FALSE;
! 					n->func_variadic = FALSE;
! 					n->over = NULL;
! 					n->location = @1;
! 					$$ = (Node *)n;
  				}
  			| CURRENT_TIMESTAMP '(' Iconst ')'
  				{
--- 11158,11164 ----
  					 * Translate as "now()", since we have a function that
  					 * does exactly what is needed.
  					 */
! 					$$ = (Node *) makeFuncCall(SystemFuncName("now"), NIL, @1);
  				}
  			| CURRENT_TIMESTAMP '(' Iconst ')'
  				{
***************
*** 11340,11435 **** func_expr:	func_name '(' ')' over_clause
  				}
  			| CURRENT_ROLE
  				{
! 					FuncCall *n = makeNode(FuncCall);
! 					n->funcname = SystemFuncName("current_user");
! 					n->args = NIL;
! 					n->agg_order = NIL;
! 					n->agg_star = FALSE;
! 					n->agg_distinct = FALSE;
! 					n->func_variadic = FALSE;
! 					n->over = NULL;
! 					n->location = @1;
! 					$$ = (Node *)n;
  				}
  			| CURRENT_USER
  				{
! 					FuncCall *n = makeNode(FuncCall);
! 					n->funcname = SystemFuncName("current_user");
! 					n->args = NIL;
! 					n->agg_order = NIL;
! 					n->agg_star = FALSE;
! 					n->agg_distinct = FALSE;
! 					n->func_variadic = FALSE;
! 					n->over = NULL;
! 					n->location = @1;
! 					$$ = (Node *)n;
  				}
  			| SESSION_USER
  				{
! 					FuncCall *n = makeNode(FuncCall);
! 					n->funcname = SystemFuncName("session_user");
! 					n->args = NIL;
! 					n->agg_order = NIL;
! 					n->agg_star = FALSE;
! 					n->agg_distinct = FALSE;
! 					n->func_variadic = FALSE;
! 					n->over = NULL;
! 					n->location = @1;
! 					$$ = (Node *)n;
  				}
  			| USER
  				{
! 					FuncCall *n = makeNode(FuncCall);
! 					n->funcname = SystemFuncName("current_user");
! 					n->args = NIL;
! 					n->agg_order = NIL;
! 					n->agg_star = FALSE;
! 					n->agg_distinct = FALSE;
! 					n->func_variadic = FALSE;
! 					n->over = NULL;
! 					n->location = @1;
! 					$$ = (Node *)n;
  				}
  			| CURRENT_CATALOG
  				{
! 					FuncCall *n = makeNode(FuncCall);
! 					n->funcname = SystemFuncName("current_database");
! 					n->args = NIL;
! 					n->agg_order = NIL;
! 					n->agg_star = FALSE;
! 					n->agg_distinct = FALSE;
! 					n->func_variadic = FALSE;
! 					n->over = NULL;
! 					n->location = @1;
! 					$$ = (Node *)n;
  				}
  			| CURRENT_SCHEMA
  				{
! 					FuncCall *n = makeNode(FuncCall);
! 					n->funcname = SystemFuncName("current_schema");
! 					n->args = NIL;
! 					n->agg_order = NIL;
! 					n->agg_star = FALSE;
! 					n->agg_distinct = FALSE;
! 					n->func_variadic = FALSE;
! 					n->over = NULL;
! 					n->location = @1;
! 					$$ = (Node *)n;
  				}
  			| CAST '(' a_expr AS Typename ')'
  				{ $$ = makeTypeCast($3, $5, @1); }
  			| EXTRACT '(' extract_list ')'
  				{
! 					FuncCall *n = makeNode(FuncCall);
! 					n->funcname = SystemFuncName("date_part");
! 					n->args = $3;
! 					n->agg_order = NIL;
! 					n->agg_star = FALSE;
! 					n->agg_distinct = FALSE;
! 					n->func_variadic = FALSE;
! 					n->over = NULL;
! 					n->location = @1;
! 					$$ = (Node *)n;
  				}
  			| OVERLAY '(' overlay_list ')'
  				{
--- 11221,11253 ----
  				}
  			| CURRENT_ROLE
  				{
! 					$$ = (Node *) makeFuncCall(SystemFuncName("current_user"), NIL, @1);
  				}
  			| CURRENT_USER
  				{
! 					$$ = (Node *) makeFuncCall(SystemFuncName("current_user"), NIL, @1);
  				}
  			| SESSION_USER
  				{
! 					$$ = (Node *) makeFuncCall(SystemFuncName("session_user"), NIL, @1);
  				}
  			| USER
  				{
! 					$$ = (Node *) makeFuncCall(SystemFuncName("current_user"), NIL, @1);
  				}
  			| CURRENT_CATALOG
  				{
! 					$$ = (Node *) makeFuncCall(SystemFuncName("current_database"), NIL, @1);
  				}
  			| CURRENT_SCHEMA
  				{
! 					$$ = (Node *) makeFuncCall(SystemFuncName("current_schema"), NIL, @1);
  				}
  			| CAST '(' a_expr AS Typename ')'
  				{ $$ = makeTypeCast($3, $5, @1); }
  			| EXTRACT '(' extract_list ')'
  				{
! 					$$ = (Node *) makeFuncCall(SystemFuncName("date_part"), $3, @1);
  				}
  			| OVERLAY '(' overlay_list ')'
  				{
***************
*** 11438,11483 **** func_expr:	func_name '(' ')' over_clause
  					 * overlay(A PLACING B FROM C) is converted to
  					 * overlay(A, B, C)
  					 */
! 					FuncCall *n = makeNode(FuncCall);
! 					n->funcname = SystemFuncName("overlay");
! 					n->args = $3;
! 					n->agg_order = NIL;
! 					n->agg_star = FALSE;
! 					n->agg_distinct = FALSE;
! 					n->func_variadic = FALSE;
! 					n->over = NULL;
! 					n->location = @1;
! 					$$ = (Node *)n;
  				}
  			| POSITION '(' position_list ')'
  				{
  					/* position(A in B) is converted to position(B, A) */
! 					FuncCall *n = makeNode(FuncCall);
! 					n->funcname = SystemFuncName("position");
! 					n->args = $3;
! 					n->agg_order = NIL;
! 					n->agg_star = FALSE;
! 					n->agg_distinct = FALSE;
! 					n->func_variadic = FALSE;
! 					n->over = NULL;
! 					n->location = @1;
! 					$$ = (Node *)n;
  				}
  			| SUBSTRING '(' substr_list ')'
  				{
  					/* substring(A from B for C) is converted to
  					 * substring(A, B, C) - thomas 2000-11-28
  					 */
! 					FuncCall *n = makeNode(FuncCall);
! 					n->funcname = SystemFuncName("substring");
! 					n->args = $3;
! 					n->agg_order = NIL;
! 					n->agg_star = FALSE;
! 					n->agg_distinct = FALSE;
! 					n->func_variadic = FALSE;
! 					n->over = NULL;
! 					n->location = @1;
! 					$$ = (Node *)n;
  				}
  			| TREAT '(' a_expr AS Typename ')'
  				{
--- 11256,11274 ----
  					 * overlay(A PLACING B FROM C) is converted to
  					 * overlay(A, B, C)
  					 */
! 					$$ = (Node *) makeFuncCall(SystemFuncName("overlay"), $3, @1);
  				}
  			| POSITION '(' position_list ')'
  				{
  					/* position(A in B) is converted to position(B, A) */
! 					$$ = (Node *) makeFuncCall(SystemFuncName("position"), $3, @1);
  				}
  			| SUBSTRING '(' substr_list ')'
  				{
  					/* substring(A from B for C) is converted to
  					 * substring(A, B, C) - thomas 2000-11-28
  					 */
! 					$$ = (Node *) makeFuncCall(SystemFuncName("substring"), $3, @1);
  				}
  			| TREAT '(' a_expr AS Typename ')'
  				{
***************
*** 11486,11560 **** func_expr:	func_name '(' ')' over_clause
  					 * In SQL99, this is intended for use with structured UDTs,
  					 * but let's make this a generally useful form allowing stronger
  					 * coercions than are handled by implicit casting.
! 					 */
! 					FuncCall *n = makeNode(FuncCall);
! 					/* Convert SystemTypeName() to SystemFuncName() even though
  					 * at the moment they result in the same thing.
  					 */
! 					n->funcname = SystemFuncName(((Value *)llast($5->names))->val.str);
! 					n->args = list_make1($3);
! 					n->agg_order = NIL;
! 					n->agg_star = FALSE;
! 					n->agg_distinct = FALSE;
! 					n->func_variadic = FALSE;
! 					n->over = NULL;
! 					n->location = @1;
! 					$$ = (Node *)n;
  				}
  			| TRIM '(' BOTH trim_list ')'
  				{
  					/* various trim expressions are defined in SQL
  					 * - thomas 1997-07-19
  					 */
! 					FuncCall *n = makeNode(FuncCall);
! 					n->funcname = SystemFuncName("btrim");
! 					n->args = $4;
! 					n->agg_order = NIL;
! 					n->agg_star = FALSE;
! 					n->agg_distinct = FALSE;
! 					n->func_variadic = FALSE;
! 					n->over = NULL;
! 					n->location = @1;
! 					$$ = (Node *)n;
  				}
  			| TRIM '(' LEADING trim_list ')'
  				{
! 					FuncCall *n = makeNode(FuncCall);
! 					n->funcname = SystemFuncName("ltrim");
! 					n->args = $4;
! 					n->agg_order = NIL;
! 					n->agg_star = FALSE;
! 					n->agg_distinct = FALSE;
! 					n->func_variadic = FALSE;
! 					n->over = NULL;
! 					n->location = @1;
! 					$$ = (Node *)n;
  				}
  			| TRIM '(' TRAILING trim_list ')'
  				{
! 					FuncCall *n = makeNode(FuncCall);
! 					n->funcname = SystemFuncName("rtrim");
! 					n->args = $4;
! 					n->agg_order = NIL;
! 					n->agg_star = FALSE;
! 					n->agg_distinct = FALSE;
! 					n->func_variadic = FALSE;
! 					n->over = NULL;
! 					n->location = @1;
! 					$$ = (Node *)n;
  				}
  			| TRIM '(' trim_list ')'
  				{
! 					FuncCall *n = makeNode(FuncCall);
! 					n->funcname = SystemFuncName("btrim");
! 					n->args = $3;
! 					n->agg_order = NIL;
! 					n->agg_star = FALSE;
! 					n->agg_distinct = FALSE;
! 					n->func_variadic = FALSE;
! 					n->over = NULL;
! 					n->location = @1;
! 					$$ = (Node *)n;
  				}
  			| NULLIF '(' a_expr ',' a_expr ')'
  				{
--- 11277,11308 ----
  					 * In SQL99, this is intended for use with structured UDTs,
  					 * but let's make this a generally useful form allowing stronger
  					 * coercions than are handled by implicit casting.
!                      *
! 					 * Convert SystemTypeName() to SystemFuncName() even though
  					 * at the moment they result in the same thing.
  					 */
! 					$$ = (Node *) makeFuncCall(SystemFuncName(((Value *)llast($5->names))->val.str),
! 											    list_make1($3),
! 											    @1);
  				}
  			| TRIM '(' BOTH trim_list ')'
  				{
  					/* various trim expressions are defined in SQL
  					 * - thomas 1997-07-19
  					 */
! 					$$ = (Node *) makeFuncCall(SystemFuncName("btrim"), $4, @1);
  				}
  			| TRIM '(' LEADING trim_list ')'
  				{
! 					$$ = (Node *) makeFuncCall(SystemFuncName("ltrim"), $4, @1);
  				}
  			| TRIM '(' TRAILING trim_list ')'
  				{
! 					$$ = (Node *) makeFuncCall(SystemFuncName("rtrim"), $4, @1);
  				}
  			| TRIM '(' trim_list ')'
  				{
! 					$$ = (Node *) makeFuncCall(SystemFuncName("btrim"), $3, @1);
  				}
  			| NULLIF '(' a_expr ',' a_expr ')'
  				{
***************
*** 11607,11622 **** func_expr:	func_name '(' ')' over_clause
  				{
  					/* xmlexists(A PASSING [BY REF] B [BY REF]) is
  					 * converted to xmlexists(A, B)*/
! 					FuncCall *n = makeNode(FuncCall);
! 					n->funcname = SystemFuncName("xmlexists");
! 					n->args = list_make2($3, $4);
! 					n->agg_order = NIL;
! 					n->agg_star = FALSE;
! 					n->agg_distinct = FALSE;
! 					n->func_variadic = FALSE;
! 					n->over = NULL;
! 					n->location = @1;
! 					$$ = (Node *)n;
  				}
  			| XMLFOREST '(' xml_attribute_list ')'
  				{
--- 11355,11361 ----
  				{
  					/* xmlexists(A PASSING [BY REF] B [BY REF]) is
  					 * converted to xmlexists(A, B)*/
! 					$$ = (Node *) makeFuncCall(SystemFuncName("xmlexists"), list_make2($3, $4), @1);
  				}
  			| XMLFOREST '(' xml_attribute_list ')'
  				{
***************
*** 13272,13280 **** makeBoolAConst(bool state, int location)
  static FuncCall *
  makeOverlaps(List *largs, List *rargs, int location, core_yyscan_t yyscanner)
  {
! 	FuncCall *n = makeNode(FuncCall);
! 
! 	n->funcname = SystemFuncName("overlaps");
  	if (list_length(largs) == 1)
  		largs = lappend(largs, largs);
  	else if (list_length(largs) != 2)
--- 13011,13017 ----
  static FuncCall *
  makeOverlaps(List *largs, List *rargs, int location, core_yyscan_t yyscanner)
  {
! 	FuncCall *n;
  	if (list_length(largs) == 1)
  		largs = lappend(largs, largs);
  	else if (list_length(largs) != 2)
***************
*** 13289,13301 **** makeOverlaps(List *largs, List *rargs, int location, core_yyscan_t yyscanner)
  				(errcode(ERRCODE_SYNTAX_ERROR),
  				 errmsg("wrong number of parameters on right side of OVERLAPS expression"),
  				 parser_errposition(location)));
! 	n->args = list_concat(largs, rargs);
! 	n->agg_order = NIL;
! 	n->agg_star = FALSE;
! 	n->agg_distinct = FALSE;
! 	n->func_variadic = FALSE;
! 	n->over = NULL;
! 	n->location = location;
  	return n;
  }
  
--- 13026,13032 ----
  				(errcode(ERRCODE_SYNTAX_ERROR),
  				 errmsg("wrong number of parameters on right side of OVERLAPS expression"),
  				 parser_errposition(location)));
! 	n = makeFuncCall(SystemFuncName("overlaps"), list_concat(largs, rargs), location);
  	return n;
  }
  
*** a/src/backend/parser/parse_utilcmd.c
--- b/src/backend/parser/parse_utilcmd.c
***************
*** 448,463 **** transformColumnDefinition(CreateStmtContext *cxt, ColumnDef *column)
  		castnode->typeName = SystemTypeName("regclass");
  		castnode->arg = (Node *) snamenode;
  		castnode->location = -1;
! 		funccallnode = makeNode(FuncCall);
! 		funccallnode->funcname = SystemFuncName("nextval");
! 		funccallnode->args = list_make1(castnode);
! 		funccallnode->agg_order = NIL;
! 		funccallnode->agg_star = false;
! 		funccallnode->agg_distinct = false;
! 		funccallnode->func_variadic = false;
! 		funccallnode->over = NULL;
! 		funccallnode->location = -1;
! 
  		constraint = makeNode(Constraint);
  		constraint->contype = CONSTR_DEFAULT;
  		constraint->location = -1;
--- 448,456 ----
  		castnode->typeName = SystemTypeName("regclass");
  		castnode->arg = (Node *) snamenode;
  		castnode->location = -1;
! 		funccallnode = makeFuncCall(SystemFuncName("nextval"),
! 									list_make1(castnode),
! 									-1);
  		constraint = makeNode(Constraint);
  		constraint->contype = CONSTR_DEFAULT;
  		constraint->location = -1;
*** a/src/include/nodes/makefuncs.h
--- b/src/include/nodes/makefuncs.h
***************
*** 75,80 **** extern TypeName *makeTypeNameFromOid(Oid typeOid, int32 typmod);
--- 75,82 ----
  extern FuncExpr *makeFuncExpr(Oid funcid, Oid rettype, List *args,
  			 Oid funccollid, Oid inputcollid, CoercionForm fformat);
  
+ extern FuncCall *makeFuncCall(List *name, List *args, int location);
+ 
  extern DefElem *makeDefElem(char *name, Node *arg);
  extern DefElem *makeDefElemExtended(char *nameSpace, char *name, Node *arg,
  					DefElemAction defaction);
*** a/src/include/nodes/parsenodes.h
--- b/src/include/nodes/parsenodes.h
***************
*** 285,290 **** typedef struct CollateClause
--- 285,295 ----
   * construct *must* be an aggregate call.  Otherwise, it might be either an
   * aggregate or some other kind of function.  However, if OVER is present
   * it had better be an aggregate or window function.
+  *
+  * Normally, you'd initialize this via makeFuncCall() and then only
+  * change the parts of the struct its defaults don't match afterwards
+  * if needed.
+  *
   */
  typedef struct FuncCall
  {